import iris
import iris.pandas as ip
import datetime
import pandas as pd
import numpy as np
import sys
import cdsapi

def extract_temp_data():
    year = ''
    while year not in ['2017', '2016']:
        year = input("Please enter required year (2016 or 2017)")
        
    output_filename = input("Enter output filename (.nc extension will be added)")
    api_info = {'2016':{'year':'2016',
                           'month': ['09','10','11','12']},
                    '2017':{'year':'2017',
                           'month': ['09','10']}}

    selected_year = api_info[year]  
    ## retreive data
    c = cdsapi.Client()

    c.retrieve(
        'reanalysis-era5-land',
        {
            'variable':[
                '2m_temperature','total_precipitation'
            ],
            'year': selected_year['year'],
            'month':selected_year['month'],
            'day':[
                '01','02','03',
                '04','05','06',
                '07','08','09',
                '10','11','12',
                '13','14','15',
                '16','17','18',
                '19','20','21',
                '22','23','24',
                '25','26','27',
                '28','29','30',
                '31'
            ],
            'time':[
                '00:00','01:00','02:00',
                '03:00','04:00','05:00',
                '06:00','07:00','08:00',
                '09:00','10:00','11:00',
                '12:00','13:00','14:00',
                '15:00','16:00','17:00',
                '18:00','19:00','20:00',
                '21:00','22:00','23:00'
            ],
            "area": "45/-73/45/-73",    # North America study region
            "grid": "1.0/1.0",  # 1.0 longitude by 1.0 latitude
            'format':'netcdf'
        },
        output_filename + '.nc') # save_file

